It feels like a trope to even say it but it amazes me how badly Google have handled the transition from Google Play Music to YT Music. For me YT Music is an inferior experience in every single way.
And on mobile GPM had a very simple functionality: a playlist containing all the songs you've downloaded offline. To the best of my knowledge YTM has no such thing, just a playlist _it makes for you_ of offline songs.
Also, the shuffle button only shuffles the current songs in queue, not the playlist your currently listening too like Spotify and GP Music do.
They couldn't move it to my main because it was legacy, but that was where I had youtube premium/red whatever. So then I needed to switch between accounts. Not fun while you are driving.
Oh then they stopped premium so I started hearing ads. Not what I want when I'm trying to calm my screaming kid in the car. Oh, and I need to keep my phone screen on.
Many of the songs aren't the same as on Google play.
Google seems to be moving toward search/email/YouTube. With few other products. Probably good, they can't handle it.
Inferior is much better than "we'll delete your music library on an undisclosed date in December".
Maybe not Apple because their fanatics will apologize for any wrong doing.